Extremely low frequency electromagnetic field measurements at the Hylaty station and methodology of signal analysis

Abstract

We present the Hylaty geophysical station, a high-sensitivity and low-noise facility for extremely low frequency (ELF, 0.03-300 Hz) electromagnetic field measurements, which enables a variety of geophysical and climatological research related to atmospheric, ionospheric, magnetospheric, and space weather physics. The first systematic observations of ELF electromagnetic fields at the Jagiellonian University were undertaken in 1994. At the beginning the measurements were carried out sporadically, during expeditions to sparsely populated areas of the Bieszczady Mountains in the southeast of Poland. In 2004, an automatic Hylaty ELF station was built there, in a very low electromagnetic noise environment, which enabled continuous recording of the magnetic field components of the ELF electromagnetic field in the frequency range below 60 Hz. In 2013, after 8 years of successful operation, the station was upgraded by extending its frequency range up to 300 Hz. In this paper we show the station's technical setup, and how it has changed over the years. We discuss the design of ELF equipment, including antennas, receivers, the time control circuit, and power supply, as well as antenna and receiver calibration. We also discuss the methodology we developed for observations of the Schumann resonance and wideband observations of ELF field pulses. We provide examples of various kinds of signals recorded at the station.

Dancing sprites: Detailed analysis of two case studies

“…[]. The ELF recordings are performed by the Hylaty ELF station in Poland [ Kulak et al ., ]. The CMC and the iCMC for a CG lightning stroke are estimated by integrating the current moment waveform during the whole variation due to the lightning stroke and during its first 2 ms, respectively [ Cummer and Lyons , ].…”

Measurement and subtraction of Schumann resonances at gravitational-wave interferometers

“…These magnetometers have sensitive bands of 3-300 Hz, with a sensitivity of ≈0.015 pT=Hz 1=2 at 14 Hz [15]. Three of the permanent installations are part of the WERA project [16], the Hylaty station in the Bieszczady Mountains in Poland, the Hugo Station located in the Hugo Wildlife Area in Colorado, USA, and the Patagonia station located in Rio Gallegos in Patagonia, Argentina [17]. These stations contain two magnetometers oriented North-South and East-West.…”

Imprints of Natural Phenomena and Human Activity Observed During 10 Years of ELF Magnetic Measurements at the Hylaty Geophysical Station in Poland

“…The station produces 2.5 MB of data per hour with a sampling frequency of 175 Hz and a dynamic range of 16 bits, and has the 3 dB frequency bandwidth of 0.03 to 55 Hz. More details of this station are described by Kulak et al (2014). The nearest station to Hylaty in Poland is operated by the Institute of Meteorology and Water Management and is located at Lesko at a distance of 36 km.…”